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Articles 8491 - 8520 of 8799
Full-Text Articles in Physical Sciences and Mathematics
The Synthesis Of Novel Macrocyclic Multidentate Compounds From Dioxodioic Acids (1), R. Elliott Asay
The Synthesis Of Novel Macrocyclic Multidentate Compounds From Dioxodioic Acids (1), R. Elliott Asay
Theses and Dissertations
A series of novel macrocyclic multidentate crown compounds have been prepared from a series of dioxodioic acids. The dioxodioic acids were prepared by treating various oligoethylene glycols or amines with maleic, succinic, citraconic, and glutaric anhydrides. The crown compounds were then synthesized from the dioxodioic acid chlorides obtained from the diacids and various oligoethylene glycols or ethylene diamine.
Real-Time Computer Optimized Scanning Potential Coulometry For Multi-Component Trace Analysis, Norman W. Petty
Real-Time Computer Optimized Scanning Potential Coulometry For Multi-Component Trace Analysis, Norman W. Petty
Theses and Dissertations
The instrumentation and methodology for real-time computer controlled scanning potential coulometry for multi-component trace analysis is described. The sensitivity limit was determined to be 10^-8 F for electrochemically reversible constituents. The sensitivity limit could be extended if measures were taken to compensate for the periodic signal found on the electrolysis current. Non-linear least squares curve fitting methods accurately resolved iron-platinum and silver-iron interferences to give accurate determinations for iron and silver. The resolving capability of this method was tested using theoretically generated scanning potential coulograms. The computer resolved sample constituents with a 1 to 100 concentration ratio and a formal …
The Dependence Of The Apparent Pk Of Ion Exchange Celluloses Of Ionic Strength, Paul Cyril Gillespie
The Dependence Of The Apparent Pk Of Ion Exchange Celluloses Of Ionic Strength, Paul Cyril Gillespie
Theses and Dissertations
Diethylaminoethyl cellulose was titrated with acid and base in various concentrations of NaCl. The pK values were determined from titration curves using a graphical technique. Two titratable groups were observed from the acid titration curve, a major and a minor group. The minor group, which represented 20% of the acid titration, was barely detectable in the base titration curve and had a salt-independent pK of 6.0. The pK of the major group was strongly salt-dependent and was approximately a linear function of log N NaCl. An equilibrium shift caused by the counter ion may explain the salt dependence. Hydrogen bonding …
Isolation, Purification, Scanning Electron Microscopy And Bacterial Dna Uptake Of Plant Protoplasts, Bronwyn G. Hughes
Isolation, Purification, Scanning Electron Microscopy And Bacterial Dna Uptake Of Plant Protoplasts, Bronwyn G. Hughes
Theses and Dissertations
Protoplasts were isolated from tobacco and barley leaves in sucrose or mannitol using commercially available cellulases and macerozymes. Barley growth and protoplast isolation and purification conditions were optimized so that protoplasts were obtained in high yields free of unwanted debris and organelles. A technique for processing barley and tobacco protoplasts for examination by scanning electron microscopy was developed in which protoplasts seem to have maintained their structural integrity. Barley and tobacco protoplasts took up 3H-B. subtilis DNA, 125I-B. subtilis DNA or 125I-M. luteus DNA as a linear function of time (0-6 hr) and DNA concentration (0-200 μg/ml). Up to 16 …
Certain Edaphic And Biotic Factors Affecting Vegetation In The Shadscale Community Of The Kaiparowits Area, Vane Orlan Campbell
Certain Edaphic And Biotic Factors Affecting Vegetation In The Shadscale Community Of The Kaiparowits Area, Vane Orlan Campbell
Theses and Dissertations
A study area on the southern extensions of the Great Basin cold desert (Kaiparowits Basin, Utah) was selected which has had varying amounts of disturbance. Areas with similar slope and exposure in the Shadscale community were sampled. At each site, soil samples were collected and percent sand, percent clay, percent silt, soluble salts, and hydrogen ion concentrations were measured. Cluster analysis based on percent frequency of the perennial species showed that eight groups or sub-communities were definable within the area sampled. Patterns within the vegetation were shown to be independent with the use of cluster analysis. Discriminant analysis on soil …
Stratigraphy And Paleontology Of The Upper Cretaceous Morden Member (Vermilion River Formation) In The Outcrop Area, Northeastern North Dakota, Fredrick D. Wosick
Stratigraphy And Paleontology Of The Upper Cretaceous Morden Member (Vermilion River Formation) In The Outcrop Area, Northeastern North Dakota, Fredrick D. Wosick
Theses and Dissertations
The Late Cretaceous Morden Member is the oldest exposed bedrock unit in North Dakota, cropping out in eastern Cavalier County in the northeastern part of the state. The Morden overlies the Greenhorn Formation and underlies the Niobrara Formation. The Canadian Morden Member of the Vermilion River Formation is used in lieu of the Carlile Formation because of the lithologic similarity and proximity to the Morden type area, and the distance from the Carlile Formation type section in southeastern Colorado.
Three principal sections were measured and sampled at 2-meter intervals for microfaunal and lithologic analysis. A single well was used for …
Western North Dakota Lignite Strip Mining Processes And Resulting Subsurface Characteristics, Laramie M. Winczewski
Western North Dakota Lignite Strip Mining Processes And Resulting Subsurface Characteristics, Laramie M. Winczewski
Theses and Dissertations
Data on subsurface conditions obtained prior to strip mining is useful in planning effective mining and reclamation procedures as well as predicting the subsurface characteristics after reclamation. The redistribution of the overburden sediments is less predictable, however.
Through field observations, the major mining factors controlling subsurface structure and overburden sediment redistribution were determined. These include the geometry of the coal body, pit sequence, pit curvature, overburden thickness and managerial input. At a given location, however, the detailed structures and distribution of sediment types within a waste bank were observed to depend upon the dragline cutting pattern, distance between dragline positions, …
Paleozoology Of Cores From The Tyler Formation (Pennsylvanian) In North Dakota, U.S.A., James C. Grenda
Paleozoology Of Cores From The Tyler Formation (Pennsylvanian) In North Dakota, U.S.A., James C. Grenda
Theses and Dissertations
A well-preserved fauna from the Tyler Formation was studied in cores from 34 wells drilled for oil in Billings, Golden Valley, McKenzie, Slope, and Stark Counties. Forty-four species of invertebrates, eleven form-species of conodonts, at least three types of fish, and at least four genera of plants· are present. Invertebrate species include 1 bryozoan, 15 brachiopods, 14 bivalves, 2 gastropods, 2 cephalopods, 2 annelids, 2 branchiopoda, at least 2 ostracodes, 2 malacostracans, 1 insect, and 1 echinoderm. Chordates include 1 "nonmarine" shark, at least 1 paleoniscoid fish, and 1 possible crossopterygian fish. A new genus and species of eocarid malacostracan …
Petrology Of The Alaskites Of The Boulder Batholith, Montana, Kenneth C. Malick
Petrology Of The Alaskites Of The Boulder Batholith, Montana, Kenneth C. Malick
Theses and Dissertations
The Boulder batholith outcrops in the Northern Rookies of western Montana. It is exposed over an area of 5700 km^2 and extends about 112 km along the continental divide from Mullen Pass on the north to 32 km south of Butte. The Boulder batholith represents an invasion of the upper zones of the crust by a large volume of fluid granodioritic quartz monzonitic magma emplaced at the close of a main orogenic episode during late Cretaceous and Paleocene time.
Eight alaskite bodies were chosen for sampling from previous field experience and from geologic maps published by the U.S.O.S. Textural descriptions, …
The Late Cenozoic Geology Of West-Central Minnesota From Moorhead To Park Rapids, Roderic L. Perkins
The Late Cenozoic Geology Of West-Central Minnesota From Moorhead To Park Rapids, Roderic L. Perkins
Theses and Dissertations
Based on lithostratigraphic and geomorphic information, the Quaternary history of an area bounded by the Red River of the North, 95°00' west longitude, 47°00' and 46°45' north latitude in west central Minnesota, includes seven geologic episodes:
Glacial advances and retreats over all or part of the study area occurred during the first six geologic episodes. The glaciers advanced either southward across northern Minnesota, entering the study area from the northeast; or across eastern North Dakota and southwestern Manitoba, entering the study area from the northwest. As a result of these glacial events the sediment of Unit A, Sebeka Formation, New …
Glacial Stratigraphy Of Southeastern North Dakota, Michael Camara
Glacial Stratigraphy Of Southeastern North Dakota, Michael Camara
Theses and Dissertations
Seven lithostratigraphic units are recognized in the glacial sediment {till) of southeastern North Dakota. Five of these units are not formally named; eventually most of these units will be correlated with formations in surrounding regions. Two of these units, Gardar and Dahlen, are formations recognized in northeastern North Dakota {Hobbs, 1975). The seven lithostratigraphic units are differentiated and correlated using the percentage of the sand, silt, and clay fractions of the till and using the proportion of igneous and metamorphic rock fragments, limestone and dolomite fragments, and shale fragments in the very-coarse-sand fraction (1 to 2 mm) of the till. …
The Effects Of Ultrasonic Vibration, Tension And Torsion On The Charge Acceptance Of The Alkaline Silver Electrode ; Ii. Potentiostatic Studies Of The Oxide Growth Rate Law For The Alkaline Silver Electrode ; Iii. The Determination Of Ionic Transport In Silver Oxide Using Radiotracer Techniques With Ag[Superscript 110m], Reed Harold Chase
Theses and Dissertations
The effect of ultrasonic vibration on the anodic oxidation of silver foil in KOH was studied. An increase in charging capacity of approximately 20% was found to be the result of cavitation erosion. Silver wire was exposed to tension and torsion during oxidation but no change in charge acceptance was caused by these stresses. The oxide growth rate on silver foil electrodes was compared to rate equations that have been proposed for other metals. Uhlig's equations for the growth of semiconductor oxides was found to describe most of the data. The data did not fit other rate equations. Determination of …
A Study Of Selected Photo Fries Rearrangements, Elwood Lloyd Loveridge
A Study Of Selected Photo Fries Rearrangements, Elwood Lloyd Loveridge
Theses and Dissertations
The Fries rearrangement of phenyl esters is reviewed and compared to the reaction when light is the source of energy. The products are different due to different mechanism of reaction. Light energy causes either free radical or concerted reactions. The S-phenylthiol esters and anilides were studied also. Although many of the rearrangements are the same, we did not see any alkyl migration nor decarboxylation type reactions with either the sulfur or nitrogen compounds. Three papers have been published from this work: Bradshaw, J. S., Knudsen, R. D. and Loveridge, E. L., J. Org. Chem., 35, 1219 (1970); Bradshaw, J. S., …
Voltammetric And Electrochemical Kinetic Studies Of The Halides And Halogens At A Platinum Rotating Ring-Disk Electrode In Anhydrous Acetic Acid, Donald Harrison Cranney
Voltammetric And Electrochemical Kinetic Studies Of The Halides And Halogens At A Platinum Rotating Ring-Disk Electrode In Anhydrous Acetic Acid, Donald Harrison Cranney
Theses and Dissertations
The electrochemical behavior of the iodine-iodide couple was investigated in both basic and neutral acetic acid solutions at a platinum rotating ring-disk electrode. Voltammetric curves were obtained and discussed. Various kinetic parameters were determined and by comparing to theoretical kinetic parameters a probable reaction mechanism was deduced. The mechanism that best fit experimental results is the following I- + S = I(S) + e- I(S) + I- = I2 + S + e (slow). The electrochemical behavior of bromine, bromide, and chloride was also investigated in the same media. Voltammetric curves were recorded and discussed with emphasis on the hysteresis …
The Glacial Geology Of Mckenzie County, North Dakota, Clark Fulton
The Glacial Geology Of Mckenzie County, North Dakota, Clark Fulton
Theses and Dissertations
Fourteen lithostratigraphic units composed of windblown, glacial, lake, slopewash, and stream sediment were distinguished in McKenzie County, The units were mapped using aerial photographs, topographic maps, and soil maps combi11ed with field e:xaminations of sediment outcrops. Eight of the units have been formally named and described in earlier studies. Four of them, however, have not been a"~ previously named and formally described .a.nu assigned names in this study. Two other units are described, but because of their limited exposure, are not assigned a formal lithostratlgraphic name. The oldest sediment exposed in the county was deposited during the Paleocene and the …
The Intermolecular Potential And Vibrational Relaxation Of The Ar-Co System, Gregory Allen Parker
The Intermolecular Potential And Vibrational Relaxation Of The Ar-Co System, Gregory Allen Parker
Theses and Dissertations
The angle, distance and vibration dependence of the Ar-CO intermolecular potential is calculated using the electron gas model to obtain the short range interaction which is smoothly joined onto the long range van der Waals tail which is obtained from accurate C_6, C_7, and C_8 coefficients. Our calculated second interaction virial coefficients are compared with experiment and with a simple adjustment of the Ar-CO potential an excellent agreement is obtained. Our spherically averaged potential is also in excellent agreement with a spherical potential inferred from high energy scattering data. Simplified expressions for the scattering amplitude and differential cross section are …
A Comparison Of Free Radical Detection Methods, Danny Kiang-Wah Pan
A Comparison Of Free Radical Detection Methods, Danny Kiang-Wah Pan
Theses and Dissertations
The methods used for free radical detection are chemical titration, spectrophotometry, Gouy magnetic measurements and NMR shift technique. The free radicals chosen for this study are Fremy' s salt (ON(SO_3 )K_2),2,2-diphenyl-1-picryl hydrazyl (DPPH) 3-carbamoyl-2,2,5,5-tetramethylpyrrolidin-1-yloxy (CTM-pyrrolidin), 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy (CTM-pyrrolin), 4-acetamido-2,2,6,6-tetramethylpiperidino-1- oxyl (ATMP) and galvinoxyl. The detectable range for each method is given. The NMR method is a fast and convenient method for the magnetic susceptibility determination of a sample in solution, with. accuracy up to ± 1%.
A Potentiometric Method, A Convenient And Rapid Technique For Determination Of The Thermodynamics Of Ionization Reactions For Water, Weak Acids, And Some Slightly Soluble Salts In Aqueous Organic Mixed Solvents, Charanai Panichajakul
Theses and Dissertations
A potentiometric method which is devised to be rapid and convenient for determining ionization constants for water, weak acids (or bases), and certain solids in mixed solvents is described. The method has been applied to the determination of ionization for water, acetic acid, benzoic acid, and phenol and the solubility product constant for silver chloride in mixtures of water with methanol, ethanol, acetone, tetrahydrofuran, and p-dioxane containing from 0 to 70 mass percent organic co-solvent at several temperatures between 10 and 40°C. Results are used to study the thermodynamics of ionization in each mixture which is discussed relative to various …
Solid-Liquid Phase Equilibria In Systems Of (I) Para-Xylene, (Ii) Mesitylene, And (Iii) N,N-Dimethylformamide ; Excess Volume Determination In Systems Containing Cyclohexane ; Calculations Of Activities For The N-Hexane + Cyclohexane System, John F. Moellmer
Theses and Dissertations
Solid-liquid phase equilibria studies were used to investigate possible compolllld formation in solutions of (i) para-xylene, (ii) mesitylene, and (iii) N,N-dimethyl-formamide (DMF) with mono- and di- halobenzenes that were selected to give a wide range of acceptor properties. Solid 1:1 intermolecular compounds were identified from solutions of p-C_6H_4F_2 with mesitylene, p-C_6H_4Br_2 with p-xylene, and p-C_6H_4Cl_2 with p-xylene. The results suggest that compound formation occurs because of favorable geometry rather than a charge transfer process. A vibrating tube densimeter was used to determine, with high precision, the densities and subsequently excess volumes of mixing of the n-hexane plus cyclohexane system. Temperature …
The Synthesis Of Analogs Of Toxoflavin And Fervenulin As Potential Antimetabolites, Bernadette Kuo Billings
The Synthesis Of Analogs Of Toxoflavin And Fervenulin As Potential Antimetabolites, Bernadette Kuo Billings
Theses and Dissertations
The synthesis of analogs of toxoflavin: 1,3,4,6-tetramethyl-1,5,6, 7-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 1,6-dimethyl-3,4-diphenyl-1,5,6,7-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 3,5,7-trimethyl-8-phenyl-2,3,4,8-tetrahydropyrido[2,3-d]-2,4-pyrimidinedione are discussed. The synthesis of analogs of fervenulin: 3,4,6-trimethyl-5,6,7,8-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 6-methyl-3,4-diphenyl-5,6,7,8-tetrahydropyrimido[4,5-c]-5,7-pyridazinedione; 2-hydroxy-3,5,7-trimethyl-4(3H)pyrido[2,3-d]-2,4-pyrimidinone are discussed. Several intermediates have been prepared: 6 -methylamino-3-methyluracil by a new method; 6-n-propylamino-3-methyluracil: 6-n-butylamino-3-methyluracil and 3-ethyl-2-ethylthio-2-hydroxy-4(3H)pyrimidinone.
Hard And Soft Nucleophilic Substitution Patterns In Amino-Methylsulfonylazines, Calvin Wilson Mccausland
Hard And Soft Nucleophilic Substitution Patterns In Amino-Methylsulfonylazines, Calvin Wilson Mccausland
Theses and Dissertations
The selectivity observed with 2,4,7-triamino-6-methylsulfonyl-pteridine when reacted with "hard" aliphatic amines and "soft" aryl-thiols resulting in amine exchange at the 2-, 4-, and 7-positions and displacement of the 6-methylsulfonyl moiety, respectively, was further investigated in other ring systems. The substrates tested were disubstituted with amino- and methylsulfonyl- moieties, and included the benzene, pyridine, pyrazine, quinoxaline, quinazoline and pteridine ring systems. The methylsulfonyl moiety is preferentially displaced by both thiols and amines with quinoxaline and quinazoline substrates, and is more reactive towards displacement by thiol than amine nucleophiles. Amine exchange occurs with the quinoxaline substrate subsequent to displacement of the methylsulfonyl …
Synthesis Of Tcne And Tcnq Derivatives And The Preparation Of Conducting Polymers, Michael L. Runge
Synthesis Of Tcne And Tcnq Derivatives And The Preparation Of Conducting Polymers, Michael L. Runge
Theses and Dissertations
Tetracyanoethylene and tetracyanoquinodimethane were reacted with various N,N-dimethyl-a, w-alkyldiamines to produce TCNE and TCNQ diamino and monoamino derivatives. NMR and ir spectra of the monoamino derivatives, 1-(N,N-dimethyl-a,w-alkyldiamino)-1,2,2-tricyanoethylenes and 7-(N,N-dimethyl-a,w-alkyldiamino)-7,8,8-tricyanoquinodimethans, indicated that these compounds exhibited strong nitrogen-hydrogen-nitrogen intramolecular hydrogen bonding. This phenomenon was corroborated by molecular weight and preliminary x-ray analyses.
The 1,1-bis(N,N-dimethyl-a,w-alkyldiamino)-2,2-dicyanoethylene and 7,7-bis(N,N-dimethyl-a,m-alkyldiamino)-8,8-dicyanoquinodimethan derivatives were polymerized with a,m-alkyldibromides containing two to six methylene groups to produce the corresponding ionene polymers. Viscosity measurements of the polymers indicated that the TCNE copolymers were generally of higher molecular weight than the corresponding TCNQ copolymers.
The two polymer series were treated with lithium …
Geology Of The Western Portion Of The Dogtooth Pluton, Lake Of The Woods Region, Southwestern Ontario, Richard H. Pilatzke
Geology Of The Western Portion Of The Dogtooth Pluton, Lake Of The Woods Region, Southwestern Ontario, Richard H. Pilatzke
Theses and Dissertations
A 10 km2 portion of a subsolvus, syntectonic or posttectonic grano dioritic intrusion located about 16 km east of Kenora, Ontario was extensively sampled for study by petrographic modal analysis and trend surface analysis. The Dogtooth pluton, the main intrusive body sampled, is part of a granitic batholith known as the Dryberry dome, which is interpreted to have been intruded into supracrustal volcanic and sedi mentary rocks about 2480 million years ago during the Kenoran Orogeny. The Longbow pluton, which was also sampled, occurs at the west margin of the Dryberry dome in contact with the supracrustal rocks to the …
Pleistocene Geology Of The Comstock-Sebeka Area, West-Central Minnesota, Curtis A. Anderson
Pleistocene Geology Of The Comstock-Sebeka Area, West-Central Minnesota, Curtis A. Anderson
Theses and Dissertations
This study is a reconnaissance of the surficial geology and a reconstruction of the late Cenozoic history of an area in westcentral Minnesota. The study area extends eastward from the Comstock area (14 miles south of Moorhead, Minnesota) in the Red River Valley to the Sebeka area (13 miles north of Wadena, Minnesota). The area is about 27 kilometres wide and 140 kilometres long.
Surface materials include Pleistocene glacial sediment and Pleistocene and Holocene fluvial, lacustrine, eolian, and bog sediment.
Four geomorphic districts are recognized. The flat Lake-Plain District is underlain by sand, silt, and clay that was deposited as …
Foraminiferids Of The Cannonball Formation (Paleocene, Danian) In Western North Dakota, William E. Fenner
Foraminiferids Of The Cannonball Formation (Paleocene, Danian) In Western North Dakota, William E. Fenner
Theses and Dissertations
In 1974 and 1975 about 2800 samples (of which 265 contained foraminiferids) of the Cannonball Formation were collected from 60 water test wells and two oil wells in Adams, Bowman, Burleigh, Divide, Dunn, Grant, Mercer, Morton, Oliver, Sioux, and Ward Counties in western North Dakota. Fifty species of benthonic foraminiferids and four species of planktonic foraminiferids were identified including eight textulariines, two milio lines and 44 rotaliines. Taxa reported for the first time from the Can nonball include: Reophax sp. (2 species), Ammobaculites expansus Plummer, Spiroplectammina wilcoxensis Cushman and Ponton, Quinqueloculina plummerae Cushman and Todd, Dentalina eocenica Cushman, Lenticulina alabamensis …
Studies Of N⁵, N¹⁰-Methylene Tetrahydrofolate Reductase From Porcine Kidney And Mouse L1210-Induced Tumor Tissues, Purification And Interaction With Antifolates, David W. Jayme
Theses and Dissertations
Methylene tetrahydrofolate reductase has been purified 1000-fold from porcine kidney and 400-fold from mouse L1210-induced tumor tissue by classical methods. The enzyme preparations have been demonstrated to be essentially free of contaminating methionine synthetase and serine transhydroxymethylase activity. Studies of the kinetic properties of the kidney and tumor enzymes, with respect to the reverse reaction using N5-methyl tetrahydrofolate as the variable substrate, have indicated Km values of 2.0 and 2.4 x 10-4 M, respectively. Inhibition of this key branch point enzyme in folate metabolism by a number of antimetabolites indicates that several of these antifolate compounds exhibit enzyme inhibition superior …
Calorimetric Determination Of The Interaction Of Cu, Fe, And V Oxides With So₂ And Measurement Of Sulfur (Iv) And Sulfur (Vi) In Particulate Samples From Utah Valley, Douglas F. Cannon
Calorimetric Determination Of The Interaction Of Cu, Fe, And V Oxides With So₂ And Measurement Of Sulfur (Iv) And Sulfur (Vi) In Particulate Samples From Utah Valley, Douglas F. Cannon
Theses and Dissertations
The adsorption of SO2 by metal oxides suspended in decane were studied by calorimetric titration. The adsorption per surface area decreases in order CuO > Cu2O > Fe2O3 > V2O5. An Andersen High Volume sampler was used to obtain particulate samples from five sites in Utah County. Particulate sulfur (IV) and sulfur (VI) was analyzed by thermometric titration with K2Cr2O7 and by a direct injection enthalpimetric determination using BaCl2. Results show that little oxidation of the S(IV) occurs after it is released from the Kennecott smelter stack.
The Effect Of Nitroalkanes On The Electrolytic Oxidation Of Tertiary Butyl Amine And Tertiary Amyl Amine, Karl Lloyd Bergen
The Effect Of Nitroalkanes On The Electrolytic Oxidation Of Tertiary Butyl Amine And Tertiary Amyl Amine, Karl Lloyd Bergen
Theses and Dissertations
The electrolyses of tert.-butyl and tert.-amyl amines were run with a voltage of approximately 3v., as measured across the cell, with and without the presence of 1-2% nitro-tert.-alkane. A graphite anode was used; the supporting electrolyte was NaClO4; the solvent was the reacting amine(s) with 10-20% water to solubilize the NaClO4. The products were azo compounds, azoxy compounds, 1,3-disubstituted ureas and traces of nitroso compounds. In the case of tert.-butyl amine di-tert.-butyl carbodiimide was also shown to be a product. The presence of nitro compounds increased the yields of azoxy and nitroso compounds and decreased the yields of azo compounds. …
The Effect Of Recreational Uses On Vegetation And Soil In The Buffalo Campground, Targhee National Forest, Island Park, Idaho, Susan Daines Foster
The Effect Of Recreational Uses On Vegetation And Soil In The Buffalo Campground, Targhee National Forest, Island Park, Idaho, Susan Daines Foster
Theses and Dissertations
The effect of trampling on vegetation and soil, as a result of recreational pressure, was studied in the Buffalo campground of the Targhee National Forest, Idaho. Site deterioration was most evident in the forty-two year old site. The tree stand had matured, but there were few young trees and tree reproduction had been reduced to ten seedlings per acre for Pinus contorta. Only two shrub species were sampled with a combined population of eight individuals per acre. Most of the grass species had been seeded; forbs provided 20% of the ground cover, 13% was bare ground and 71% litter. The …
Synthesis And Stereochemistry Of 2,6,10-Triazatricyclo [5.2.1.0⁴ ¹⁰] Decane Derivatives, Susan Elaine Foulger
Synthesis And Stereochemistry Of 2,6,10-Triazatricyclo [5.2.1.0⁴ ¹⁰] Decane Derivatives, Susan Elaine Foulger
Theses and Dissertations
The synthesis and stereochemical aspects of derivatives of the new ring system 2,6,10-triazatricyclo [5.2.1.04,10] decane are discussed. Sythesis of 2-nitro-2-methyl-1,3-disubstitutedaminopropanes, followed by reduction of these compounds to 2-amino-2-methyl-1,3-disubstituted aminopropanes afforded the necessary starting materials for a cyclization reaction similar to that resulting in already known 2,6-dioxa-10-azatricyclo [5.2.1.04,10] decanes. Reaction of the triamines with 2,5-hexanedione resulted in 2,6-disubstituted-1,4,7-trimethyl-2,6,10-triazatricyclo [5.2.1.04,10] decanes. The stereochemical aspects of this ring system are interesting from the standpoint of nitrogen inversion barriers on nitrogens 2 and 6. Existence of a high inversion barrier for these nitrogens in shown by isolation of different diastereomers of the tricycle. Methods …